Inverse multiplexing techniques can be used to support higher frequency bandwidth data transmission using several connections instead of a single broadband connection such as a fibre-optic cable or coaxial link. IMA-is an inverse multiplexing technique related to ATM E1/T1 connections. The inverse multiplexing protocol for ATM used by IMA does not relate to the data transfer medium. In the IMA-inverse multiplexing technique the data transfer quality of connection lines is not measured and evaluated.
As can be seen from FIG. 1 a plurality of DSL-connection lines is provided within a cable trunk. Each DSL-connection line consists of a twisted-pair telephone line made of copper. Environmental noise and signal disturbances created by other DSL-connection lines within the same cable trunk and the signal attenuation of the twisted-pair telephone line limit the amount of total bandwidth available over the aggregated connection lines. The cross-talk between the different DSL-connection lines reduces the possible operating distance for data transmission. Since in the IMA inverse multiplexing technique the quality of the data transmission line is not evaluated a data transmission line is activated which does not provide the best possible data transmission.